I have a kenwood tm-742a tri-bander that the memory battery is good ( 2.8 volts ) but an hour after turning the 12 volts off and then back on , the freq's are gone , but if you let 12 volts hooked up and just turn the power off by the switch on the radio its OK ?????????
doe's anyone have any hints or ideas of a fix ??????
I'm out of ideas
thanks
mike

Old post I know but thought i would just answer it in case anyone else needs to know.

The 641/642/741/742/941/942 series use the same lithium back up battery.

The Kenwood "East Coast Parts" part number = W09-0573-05 and this battery
if it falls close to 3.0 V is just about exhausted and should be replaced. It should
have an operational voltage of about 3.3V under load(in circuit load).